Methods and apparatus for the electronic input and output of multicolor images using laser scanning techniques are known. Such methods and apparatus are disclosed, for example, in U.S. Pat. Nos. 3,956,658; 4,054,916; 4,093,964; 4,276,567; 4,319,268; and 4,432,613.
At the image input stage, an original multicolor image is raster scanned with a laser beam to obtain a plurality of photoelectronic signals representative of the original multicolor image. The signals are electronically separated into single color images, for example, red, green and blue images, or cyan, magenta and yellow, (referred to hereinafter as color separations). Each color separation is then electronically converted via computers to analogue or digital representations of each color separation.
The thus obtained analogue or digitized color separations signals may then be electronically manipulated to enhance or otherwise adjust each set of signals. After such electronic manipulations, each set of signals are stored until output of the original multicolor image is desired.
At the output stage, each color separation signal is passed to a computer which addresses an electro-optical modulator. The modulator modulates a laser beam adapted to raster scan a multilayer color photographic imaging element. In general, each layer of the element has been spectrally sensitized to different wavelengths of light. Each layer must therefore be exposed to different laser beam. The laser beam is modulated, according to the analogue or digitized color signal of each color separation. The thus modulated laser beam raster scans the color photographic element to produce a single color separated image on the photographic element.
A complete color rendition of the original multicolor image is obtained by reproducing each color separation separately. Each reproduced color separation is then registered with the other color separations to obtain a complete rendition of the multicolored original. In some apparatus more than one electro-optically modulated laser beam is used with an equal number of color photographic elements to produce all of the color separations at the same time.
The problem is that in either case the different color separations must still be registered to produce a complete rendition of the multicolored original image and a different wavelength laser beam is required for each layer of the photographic element.
Methods in which the need to register each color separation and the need for more than one wavelength laser beam is avoided are highly desirable.